Conveying device

ABSTRACT

A portable conveying device comprising an inclining base having a conveyor belt, a plurality of articulating conveying elements having powered cargo rollers defining a conveying device transport plane, the conveying elements extendable from and retractable into the base by drive means. The drive means may include a pair of spaced-apart spur gears which have teeth that engage with rack teeth of the conveying elements. The conveying device may include a hollow universal joint having axes of rotation lying substantially in the same plane.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to conveying devices, and morespecifically to conveying devices having drive mechanisms to selectivelyextend and retract conveying elements, and particularly to conveyingdevices having drive mechanisms to selectively extend and retractconveying elements from an aircraft baggage loader.

2. Background Information

Baggage loading devices are common. A typical device includes a vehicleequipped with an endless belt upon which luggage or other items areplaced. Movement of the belt conveys the luggage from one end of thevehicle to the other end. An airplane loading vehicle preferablyelevates at an angle so the luggage is transported from a lower leveland into higher positioned cargo area of the airplane. In some instancesadd-on conveyors are included with the main belt-driven loader.

One example of such an add-on conveyor is found in U.S. Pat. No.5,584,376 to Voldby. The add-on conveyor in Voldby is generallypositioned in a retracted state beneath the main belt loader of theapparatus. The conveyor may be extended into the cargo compartment ofthe aircraft. A user manually pushes the conveyor into position while anassistant in the cargo compartment guides the end of the conveyor. Theconveyor can be withdrawn progressively by manually pulling the conveyorfrom the outside in the opposite direction. At least a certain number ofthe rollers of the conveyor may include driving means to power therollers which in turn convey baggage or other items. The conveyorincludes a flexible driving means, such as a cardan chain, which has twodegrees of freedom, one along the curve and the other up/down inrelation to a horizontal plane. Examples of such chain include the type“Uni-slat top” or “Uni-Flex”, both from the firm Uni-Chains Int. A/SVejle, Denmark. A chain of the latter type essentially consist ofY-shaped chained links, linked together so that the chain can be curvedlike a bike chain, but can also be bent sidewards in a curve. Theslat-variety includes elements with a slat of flattened surface that arelinked together and have similar movement as a Y-shaped variety. Neitherinclude a hollow opening disposed for running of cables within thechain-like structure.

Another example of a conveyor device is found in PCT ApplicationPublication No. WO 2005/073110 A1 entitled Conveying Device, by MartinVestergaard, published Aug. 11, 2005. The conveyor device in thatapplication is silent as to whether and/or how the device is extendedfrom or retracted into the aircraft or other base. The conveyor devicein that application includes a variety of mechanisms for articulation ofrespective conveying elements. The device also includes an embodimentwhere the conveying device of that invention is arranged underneath thedevice for transporting the luggage from the cargo hold to the luggagetrolley placed on the ground. This is done by arranging a box-likestructure underneath the conveyor such that the conveying deviceaccording to that disclosure can slide out of and into that box-likestructure. For that purpose, a guide rail is arranged inside the boxsuch that the chain box elements 4 of the conveying device according tothat disclosure may by means of guidance rollers roll inside the guiderail such that it is relatively easy to eject or insert the conveyingdevice into the conveyor. While the device of Vestergaard shows a hollowchain box 4 as indicated in prior art FIG. 15 by reference number 43 forplacing different means for powering the rollers, wires etc. (which FIG.15 generally corresponds to FIG. 15 of the Vestergaard PCT application),such particular structure of FIG. 15 or disclosure does not show auniversal joint for articulation to achieve two degrees of freedom.

Another example of a conveyor device in use outside the United Statesand generally demonstrated at www.powerstow.com includes a retractableconveyor having multiple rollers. This device is marketed by Power StowA/S of Denmark under the name Rollertrack. The retraction and extensionof the conveyor units appears to be powered; yet the specifics of howsuch motion is obtained, such as with a worm drive or jack screw orother mechanism, is not apparent from the disclosure. There is nodisclosure of the conveyor units having a yoke for articulation toachieve two degrees of freedom or to swivel about two axes. What isapparent in the Rollertrack device, however, is the need for use oftracking rollers to fill a gap between the conveyor belt and theextending rollers.

Other examples of conveyor devices having a retractable conveyor arefound in U.S. patent application Ser. No. 10/169,361 to Thogersen,publication No. US 2003/0091415, and U.S. patent application Ser. No.10/720,471, publication No. US 2004/0105740. These applications show aretractable conveyor constructed for storing in a generally foldedconfiguration. The retractable conveyor units include an endless belt.In one embodiment, the moving of the conveyor units to and from thecargo compartment of an aircraft is carried out by means of a driving,endless conveyor belt which cooperates with the bottom side of theconveyor units, such as by way of friction; or the conveyor part ispushed and moved into the cargo compartment; or the invention isgenerally silent as to the particulars of how the conveyor units aredriven or retracted or extended. The pivoting of respective conveyorunits requires a complicated design and accommodates pivoting in limiteddirection. For instance, the individual conveyor units pivot in abottom-to-bottom relationship but do not freely pivot in a top-to-toprelationship (i.e., they fold downward (bottom-to-bottom) with respectto each other but there is no showing that they fold top-to-top, orupward with respect to each other).

The present invention, however, provides a novel conveying device andadvantages over prior designs. The device includes a drive mechanismwhich accommodates for ease of extension/retraction of the conveyingelements of a conveyor. The conveying elements also include anadvantageous hollow universal articulating joint for increasedperformance. Numerous other advantages and novel features of the presentinvention are disclosed.

SUMMARY OF THE INVENTION

The present invention is directed toward a conveying device comprisingat least a first conveying element comprising a supporting rail, a cargoroller positioned above the supporting rail, and the supporting railhaving at least one rack tooth. The device may further include a drivemeans for engaging the rack tooth to drive the conveying element. Aplurality of conveying element articulate with adjacent conveyingelements. The drive means may include a spur gear, and preferably a pairof spaced apart spur gears to engage with a series of rack elements toaccommodate retraction/extension of the retractable conveyor.

A further aspect of the invention includes a conveying device comprisingat least a first spur gear, and at least two conveying elements eachhaving a cargo roller, the at least two conveying elements defining agroove in which at least one tooth of the spur gears inserts. The devicemay further include at least one of the conveying elements having asupporting rail, the supporting rail having a rack element against whichthe at least one tooth abuts. A universal joint may connect adjacentconveying elements, with the universal joint being hollow to allow wiresto be strung through the device to power the cargo rollers. Theuniversal joint includes a yoke defining lines of axis lying generallyon the same plane to accommodate a compact arrangement having desireddegrees of movement.

A further aspect of the present invention includes a portable conveyingdevice comprising an inclining base having a conveyor belt, a pluralityof articulating conveying elements having powered cargo rollers defininga conveying device transport plane, the conveying elements extendablefrom and retractable into the base by drive means. The drive means mayinclude a pair of spaced-apart spur gears which have teeth that engagewith rack teeth of the conveying elements. The conveying device mayinclude a hollow universal joint having axes of rotation lyingsubstantially in the same plane.

The above summary of the present invention is not intended to describeeach illustrated embodiment, aspect, or every implementation of thepresent invention. The figures and detailed description that follow moreparticularly exemplify these and other embodiments and further aspectsof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing description of various embodiments of the invention inconnection with the accompanying drawings, in which:

FIG. 1 is a plan view of a conveyor made in accordance with the presentinvention.

FIG. 2 is a front elevation view of a conveyor and conveying element ofthe present invention.

FIG. 3A is an elevation view of a conveyor of FIG. 1 with a retractableconveyor portion retracted and with portions of a base conveyor removedfor clarity.

FIG. 3B is an elevation view of the conveyor of FIG. 1 with beltconveyor elevated and with portions of the unit removed for clarity.

FIG. 4 is a partial elevation view of the conveyor of FIG. 3.

FIG. 5 is a section view taken along line 5-5 of FIG. 4

FIG. 6A is a left side elevation view of the conveyor and element ofFIG. 2.

FIG. 6B is a section view taken along line 6B-6B of FIG. 2.

FIG. 7 is a partial elevation view of the conveyor of FIG. 3 withportions removed for clarity.

FIG. 8 is a partial perspective view of a conveyor of the presentinvention with portions removed for clarity.

FIG. 9 is a partial plan view of the conveyor of FIG. 8.

FIG. 10 is a partial bottom perspective view of components of a conveyorof the present invention.

FIG. 11 is a partial elevation view of a further aspect of the presentinvention.

FIG. 12 is a partial plan view of a further aspect of the conveyor ofthe present invention.

FIG. 13 is a partial plan view of a further aspect of the conveyor ofthe present invention.

FIG. 14A is a perspective view of a yoke component of the presentinvention.

FIG. 14B is a top view of a further aspect of the yoke component.

FIG. 15 is an elevation view of a prior art device.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not necessarily to limit the invention ofthe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention and as defined by the appendedclaims.

DETAILED DESCRIPTION OF THE INVENTION

The invention is directed to a portable conveyor comprising an incliningbase having a conveyor belt, a plurality of articulating conveyingelements having powered cargo rollers defining a conveying devicetransport plane, the conveying elements extendable from and retractableinto the base by drive means. The drive means may include a pair ofspaced-apart spur gears which have teeth that engage with rack teeth ofthe conveying elements. The conveying device may include a hollowuniversal joint having axes of rotation lying substantially in the sameplane.

Referring now to FIG. 1, a conveyor according to the present inventionis generally depicted with reference to numeral 20. In one aspect,conveyor 20 includes a base 22 and a retractable conveyor 24. Base 22 ispreferably a belt conveyor as is common in the aircraft ground supportequipment environment. Typically base 22 includes a conveyor belt 44which typically includes an endless belt driven by a head stock pulley46 and supported by multiple conveyor belt rollers 45. Belt 44 travelsover return idler 47 as is commonly understood. A variety of conveyorbelt devices may be used in conjunction with the present invention.While preferable, it may be appreciated that base 22 need not be limitedto a conveyor belt mechanism.

In FIG. 1, retractable conveyor 24 is depicted in an extended position.It may be appreciated that conveyor 24 may be placed within the cargohold of an aircraft for transport of cargo items (cargo not shown).Retractable conveyor 24 includes a number of conveying elements 26 whicharticulate with respect to adjacent elements 26 and accommodateextension of conveyor 24 into various positions. Conveyor 20 preferablyincludes a docking platform 25 intended to rest within the cargo holdarea of an aircraft. Front end conveying element 27 is preferablypositioned on platform 25 when in a retracted state. Each of conveyor20, base or belt conveyor 22, retractable conveyor 24 and conveyingelement 26 are conveying devices as that term is used herein.

Referring to FIG. 2, conveyor 20 includes at least one conveying element26. Conveyor element 26 includes a wire harness box 28 formed generallyof a box channel plate 70 and box plate 72. Alternatively, a hollowsection tube may be used. Box channel plate 70 is generally U-shaped andwhen fitted with box plate 72 forms a generally rectangular channel 78preferably running the length of wire harness box 28. Box channel 78accommodates for running of power or control wires (not shown) thelength of conveyor 20. Conveying element 26 includes supporting rail 30.Preferably conveying element 26 has a pair of supporting rails 30affixed on either side of wire harness box 28. Supporting rails 30 arepreferably welded to wire harness box 28. Supporting rail 30 includesshoulder 32 which is preferably a channel or U-shaped and extendsupwards from rail 30. Shoulders 32 on each end of conveying element 26support cargo roller 34. Cargo roller 34 rotates to convey items such ascargo. Sleeve 35 is placed over cargo roller 34 for desiredcircumference and traction. Inside cargo roller 34 is a powering means,such as a motor (powering means and motor not shown) for rotating roller34. Typically powering means is an electric motor. Wires (not shown) forpowering electric rotation motor are fed through box channel 78, alongsupporting rail 30, along shoulder channel 32 and preferably throughhollow bolt 50. Supporting rail 30 includes transport roller 36,generally affixed opposite cargo roller 34. Preferably conveying element26 includes at least two transport rollers 36. Transport rollers 36allow element 26 to roll upon an aircraft cargo bed (not shown) or othersurface. Wire harness box 28 includes at least one guiding roller 74which is configured to roll within guide rail 80 (see FIG. 5) and toalign and guide conveying element 26 in an out of base 22. Supportingrail 30 preferably includes guidance rollers 75 which also roll withinguide rail 80 to assure transport rollers 36 of conveying element 26roll upon track 82 (see FIG. 5) of base 22. It may be appreciated thattrack 82 runs at least substantially the length of base 22. Preferablyrectangular tube 85 is included to provide support to conveyor 22.Preferably UHMW material 87 is positioned along the assembly ofconveying elements 26 to accommodate smooth extraction/retraction.Preferably UHMW material has general dimension of ½ inch thick by 1½inches wide and conveniently spaces or allows box 28 to be aligned. UHMWmaterial 87 preferably runs the length of the assembly of elements 26 toprevent tipping and maintaining level positioning of elements 26.

Conveying element 26 includes at least one rack tooth 52. Rack tooth 52is preferably affixed to supporting rail 30. It may be appreciated thatrack tooth 52 may be integrally connected with rail 30. As shown in FIG.6B, rack tooth 52 includes rack wall 54 and rack lower wall 56.Preferably rack wall 54 has a concave cross-section and rack lower wall56 has a convex cross-section. Such concave and convex cross-sectionaccommodate for improved driving of conveying element 26 to retract orextract conveying element 26 from a base 22. Preferably rail 30 includesa rack tooth 52 at a front side 88 and at a rear side 90 of rail 30.More preferably rack tooth 52 is a single unit that wraps from frontside 88 to rear side 90 of rail 30 as shown in FIG. 6B. Preferably racktooth 52 is fastened into rail 30 with fastening means 89 such as a boltor the like.

FIG. 3 is an elevation view of conveyor 20 with a retractable conveyorportion 24 retracted. Conveyor 20 includes base 22 which may preferablybe a belt conveyor. Portions of a base conveyor have been removed forclarity. Multiple conveying elements 26 are stored beneath conveyor belt44 and are extracted or driven by drive means 39. As shown in FIG. 4,drive means 39 includes a spur gear 38 having fingers 42. Adjacentconveying elements 26 define grooves 40. Finger 42 inserts into groove40 and upon rotation of spur gear 38, drives a conveying element 26.Preferably finger 42 abuts rack tooth 52. As finger 42 rotates itpreferably successively abuts both rack wall 54 and rack lower wall 56.Such action accommodates efficient driving of conveying elements 26.

As shown in FIG. 5, conveyor 20 preferably includes two spur gears 38.Each spur gear engages with a respective series of rack teeth defined bythe individual rack tooth 52 of conveying elements 26. Preferably eachspur gear 38 is affixed to a spur gear shaft which is rotatably affixedto base 22. Preferably spur gear 38 has a generally square center boreto mate with shaft 48 which is preferably made of square stock to lockspur gear 38 and to keep spur gear 38 from slipping about shaft 48.Preferably spur gears 38 a, 38 b are spaced apart to engage rack tooth52 on either side of wire harness box 28 to accommodate efficientdriving of conveying elements 26.

While drive means 39 is preferably hydraulically powered, it may beappreciated that drive means may also be electrically powered.Preferably hydraulic drive means 39 includes a hydraulic motor and brakemechanism 92 to prevent back flow of elements 26 when conveyor 20 is inan elevated position. The brake 92 includes a brake release valve, whichwhen hydraulically powered, allows for release of the brake andsubsequent movement of the conveying elements 26.

Spur gear 38 may be made of a variety of metals or other items, andpreferably spur gear 38 is made of a nylon type of ingredient such asthose that may contain nylon and molybdenum disulphide such as Nylatron®GSM, or is made of phenolic or a synthetic resin type of material.Preferably fingers 42 are spaced apart or have a “pitch” generally shownby the arrow X of FIG. 4. Preferably the pitch is about 6 inches.Preferably spur 38 gear has a pitch diameter of about 19 inches.Preferably spur gear 38 is positioned toward a front end of conveyor 20to accommodate efficient extraction/retraction of conveyor 24.

FIG. 6A and FIG. 6B show conveyor 20 from an elevation view. FIG. 6Aincludes conveying element 26 with shoulder 32 extending generallyupward from supporting rail 30. Preferably shoulders 32 are welded torails 30. Shoulders 32 preferably include a wire channel 71 to receivewires running from wire harness box 28 to power cargo roller 34.Preferably at least two guiding rollers 74 are positioned on either sideof transport rollers 36 to accommodate for efficient alignment withinguide rail 80.

Conveyor 20 includes means for pivoting 58 about at least two andpreferably three axes. Preferably each conveying element 26 includes aU-joint or universal joint 58 to accommodate for multiple degrees ofmotion so that elements 26 may articulate with respect to each other andfrom side-to-side and over surfaces having varying undulations.Preferably universal joint 58 is a “hollow” U-joint in that it has ahollow space to accommodate insertion of wires through conveying element26. Preferably universal joint 58 includes means for pivoting, or yoke60. Preferably yoke 60 has a generally rectangular cross section and ahollow center or yoke channel 61. More preferably yoke 60 is a tube-likestructure. Preferably yoke 60 has an outer dimension less than or equalto an inner dimension of wire harness box 28 as shown in FIG. 2.

Yoke 60 is preferably a rectangular shaped swivel component havingapertures 77 a-77 d located preferably on each of its four faces 73 a-73d as generally shown in FIG. 14A. Preferably face 73 a is opposite andparallel to face 73 c, and face 73 b is opposite and parallel to face 73d. Preferably each yoke face 73 a, 73 b, 73 c, and 73 d include anaperture 77 positioned substantially at a center portion of therespective faces 73. Axis 79, which is generally a horizontal axis,generally runs through apertures 77 b and 77 d; and axis 81, which isgenerally a vertical axis, generally runs through apertures 77 a and 77c. Preferably axis 79 and axis 81 lie on a common plane. Positioning ona common plane accommodates for a more compact design of universal joint58. More preferably axis 79 intersects with axis 81 at a center portionof yoke channel 61. Such centralized alignment accommodates for moreefficient and more uniform swiveling of respective conveying elements26. It may be appreciated that each pair of apertures accommodatesinsertion of fasteners 76 a-76 d to allow for pivoting about respectivefasteners. For instance, fasteners 76 a and 76 c accommodate pivotingabout vertical axis 81 to accommodate a generally side-to-side pivotingof respective elements 26. Such side-to-side pivoting is best shown ingeneral along the curve of retractable conveyor 24 in FIG. 1. Fasteners76 b and 76 d accommodate pivoting about a horizontal axis 79 toaccommodate a generally up-and-down pivoting between respective elements26. Such up-and-down pivoting is best shown in general in FIG. 4 aselements 26 curve vertically along track 82. This side-to-side andup/down motion of elements 26 is referred to as having two degrees offreedom, one along the curve and the other up/down in relation to ahorizontal plane. More particularly, universal joint 58 has at least twodegrees of freedom, and preferably three degrees of freedom (i.e., joint58 pivots or allows for pivoting about at least two axes, and preferablythree axes as stated below).

As shown in FIG. 14B, yoke 60 preferably has opposing apertures 77 a and77 c which lie generally on vertical axis 81. Preferably, apertures 77 aand 77 c are elongated or oval shaped or otherwise have a slot 91. Slot91 is somewhat exaggerated in its scope of elongation for demonstration.Oval shaped apertures 77 a and 77 c allow conveying elements to rotateor twist about axis 93 which runs generally normal to axis 79 and axis81, and generally longitudinally through center of yoke 60. Slot 91allows for a third degree of freedom, namely rotational freedom. Assuch, conveying element 26 is allowed to rotate about theabove-referenced longitudinal axis 93, and transport roller wheels 36which lie on either side of wire harness box 28 may accommodate travelover varying or uneven surfaces by means of rotation or movements due toslot 91. It may be appreciated that slot 91 allows for a certain amountof “slop” and that rotation or movement is not confined to rotation ormovements about axis 93 but may vary depending on the case. Preferablymeans for pivoting 58 and 60 accommodates range of motions of, forinstance, up/down of plus/minus about 36 degrees, side-side ofplus/minus about 12 degrees, and rotation of plus/minus about 2.4degrees. It may be appreciated that side-side motion may be limited bybumpers 33.

Rotation about axis 79 allows adjacent conveyors 26 to be pivoted suchthat respective cargo rollers 34 may either draw closer together orfurther apart depending upon the undulation of rail 82 or of theundulation of a cargo hold, platform or other surface. It may beappreciated that use of such universal joint 58 may accompany a varietyof conveying devices and is not limited to those devices having a drivemeans 39 as recited but may be used in conjunction with other mechanismsthat might employ a worm drive or jack screw drive or other mechanism toextend conveying elements.

Conveying element 26 includes generally opposing front tabs 62 andgenerally opposing rear tabs 64. Rear tabs 64 align with yoke 60 atfaces 73 b, 73 d while adjacent conveying element 26 has front tabs 62which align with yoke 60 at faces 73 a, 73 c. Tabs 62, 64 are alignedand rotatably fastened at apertures 65 and through box fastenerapertures 77 b, 77 d. As best shown in FIG. 9 and FIG. 10, tabs 62, 64are tapered (such as at tapered edge 63) to accommodate articulation orswivel to achieve a desired range of motion of respective conveyingelements 26. Preferably terminating end 67 has a width w less than awidth z of harness box 28 and yoke 60. It may be appreciated thatadjacent conveying elements may freely articulate while at the same timecables (cables not shown) may be strung through yoke channel 61 and boxchannel 78. Preferably wire harness box 28 includes access port 68 toaccommodate access to cabling that runs through wire harness box 28.Preferably, harness box 28 is modular such that successive harness boxes28 may be connected to and/or interchanged with adjacent harness boxes28.

FIG. 10 is a bottom perspective view of the invention with various partsremoved for clarity. A variety of roller flanges 83 project from anunderside of rails 30 for attachment of rollers 36, 75. Shoulders 32extend upward from rails 30. While rack tooth 52 is shown to straddlerail 30, it may be appreciated that rails 30 may be of wider dimensionso that rack tooth 52 is an integral part of rail 30.

As shown in FIG. 7, FIG. 8 and FIG. 9, conveying elements 26 a, 26 b,and 26 c are connected with respective universal joints 58. Finger 42 ainserts into groove 40. A portion of finger 42 a engages rack lower wall56 of element 26 b while another portion of finger 42 a preferablyengages with rack wall 54 of element 26 a. Likewise, finger 42 b engageswith rack lower wall 56 of element 26 b while another portion of finger42 b preferably engages with rack wall 54 of element 26 c. It may beappreciated that as gear 38 rotates either clockwise orcounter-clockwise, various portions of fingers 42 will engage withvarious portions of rack teeth 52 to thereby drive or otherwise retractor extract elements 26. Fingers 42 are designed with crests 42 x andvalleys 42 y to match grooves 40 and rack teeth 52 for a smooth drivingmotion of elements 26.

FIG. 3B shows one typical example of a conveyor 20 where base 22 is abelt conveyor having scissors lift. Scissors lift 20 includes anactuator 98 for inclining conveyor belt 44 relative to a relativelyhorizontal position as shown in FIG. 3A. Conveyor 20 preferably is avehicle and includes wheels 99 or other transporting means to transportconveyor 20 from place to place. Preferably conveyor includes dockingplatform 25 upon which front end conveying element 27 may rest.Preferably docking platform 25 rotates to accommodate leveling ofelement 27 and to allow for flush engagement of platform 25 with anaircraft cargo floor or other surface. Preferably, conveyor includes aleveling sensor and/or controller to automatically adjust the level ofplatform 25 to accommodate placement at the area of entry of platform 25into the aircraft. Leveling mechanism includes a hydraulic bleed toallow platform 25 to move freely or to float into desired position. Onceplatform is sensed to be in a level position relative to a cargo entryarea, elevation movement of conveyor 22, such as a scissors conveyor,ceases automatically.

Preferably element 27 includes an endless belt conveyor 44, which alsomay preferably include a flap to be raised or lowered to accommodatevarious angles for unloading cargo. Handle 29 slides within handleblocks 29 a, 29 b to operate extraction or retraction of elements 26,27. As a user grasps and slides handle 29 in the direction of arrow A(FIG. 4), switches or controls activate drive means 39 which operates byrotating in a clockwise direction to extend element 27 in the directionof arrow A. Element 27 preferably includes drive roller 31 whichpreferably extends substantially the width of element 27 and rotates ashandle 29 slides. Drive roller 31 is preferably powered by an electricdrive motor. Drive roller 31 assist in smooth extraction of elements 26which may otherwise compress upon adjacent elements 26 causingretractable conveyor 24 to otherwise buckle or misalign. In retractionmode, drive roller 31 may be unpowered and rotate freely to allow drivemeans 38 to control retraction. Element 27 may also include a controlarea (not shown) for housing control mechanisms and systems foroperation of the various belts, rollers and drive mechanisms of conveyor20.

In operation, after conveyor 20 is positioned adjacent an aircraft andplatform 25 is leveled to the cargo hold area, a user extractsretractable conveyor 24 by grasping handle 29 and extending the conveyorto the cargo hold area. Handle 29 operates drive means 39 which powers,for instance, spur gear 38 and may also power drive roller 31. As spurgear 38 rotates, individual fingers 42 engage with respective grooves 40defined by the plurality of conveying elements 26. Fingers 42 abut rackteeth 52 for efficient driving of elements 26. Guiding roller 74 andguidance rollers 75 operate to maintain elements 26 on track 82.Individual elements 26 swivel as they travel over undulations such asthe curved track 82 and further swivel from side-to-side as desired toenter various cargo hold areas. The method of operation includesproviding a conveyor 20 as described herein, positioning the conveyor 20adjacent an aircraft, extracting conveyor 24, and placing cargo uponconveyor 24.

Referring to FIG. 11, a further aspect of the conveyor 20 is shown. Cogbelt 94 rotates about cog belt shaft 96 where fingers 42 successivelyengage within respective grooves 40 to drive conveying elements 26.Fingers 42 are configured to engage with rack tooth 52 and to matchgenerally concave rack wall 54 and generally convex rack lower wall 55.A pair of cog belts 94 may be provided on either side of wire harnessbox 28 so as to have fingers 42 engage with at least two rack tooth 52of each supporting rail 30. Cog belt 94 may have multiple fingers 42 andmay span to engage with more than one groove 40. Cog belt 94 ispreferably made of a rubberized material so that fingers 42 whichoperate similar to treads may flex as they travel around cog belt shaft96 into driving position.

Referring to FIG. 12, a further aspect of the conveyor 20 is shown.Drive means 39 includes a pair of spaced apart spur gears 38 arranged atrespective ends of elements 26. Bumpers 33 operate as rack tooth 52having rack wall 54 and rack lower wall 56. Fingers 42 engage bumpers 33to drive elements 26. As spur gears 38 rotate, elements 26 are extendedfrom or retracted to base 20. With reference to FIG. 13, a furtheraspect of the invention is shown, where drive means 39 includes cogbelts 94. As belts 94 travel about shaft 96, fingers 42 engage withbumpers 33 having rack tooth 52 to drive elements 26.

The terms and descriptions used herein are set forth by way ofillustration only and are not meant as limitations. Those skilled in theart will recognize that many variations are possible within the spiritand scope of the invention as defined in the following claims, and theirequivalents, in which all terms are to be understood in their broadestpossible sense unless otherwise specifically indicated.

1. A conveying device comprising: at least a first conveying element comprising: a supporting rail; a cargo roller positioned above said supporting rail; and said supporting rail having at least one rack tooth, where said supporting rail is substantially parallel to an axial direction of said cargo roller.
 2. The device of claim 1 wherein said supporting rail includes a shoulder and at least one transport roller, said cargo roller affixed to said shoulder.
 3. The device of claim 1 wherein said device includes a wire harness box, said supporting rail affixed to said wire harness box.
 4. The device of claim 1 further comprising a drive means for engaging said rack tooth and driving said conveying element.
 5. The device of claim 4 wherein said drive means is one selected from the group consisting of a gear, a spur gear, and a clog belt.
 6. The device of claim 1 further comprising a base, a drive means affixed to said base, and a second conveying element, said drive means for driving said first and said second conveying elements from said base.
 7. The device of claim 1 wherein said supporting rail includes a rack tooth on a front side and on a rear side of said supporting rail.
 8. The device of claim 1 wherein said rack tooth includes an upper rack wall having a generally concave cross-section and lower rack wall having a generally convex cross section.
 9. The device of claim 1 further comprising: a portable vehicle having a base, said base having a conveyor belt; at least a first and a second spur gear rotatably affixed to said base; and a plurality of articulating conveying elements having powered cargo rollers, said conveying elements extendable from said base, said conveying elements defining a plurality of grooves in which teeth of said first and second spur gears engage to operatively extend and retract said conveying elements.
 10. A conveying device comprising: at least a first spur gear; at least two conveying elements each having a cargo roller, said at least two conveying elements defining a groove in which at least one tooth of said spur gear inserts; and at least one of said conveying elements has a supporting rail, where said supporting rail is substantially parallel to an axial direction of said cargo roller.
 11. The device of claim 10 where said supporting rail having a rack element against which said at least one tooth abuts.
 12. A conveying device comprising: at least a first spur gear; at least two conveying elements each having a cargo roller, said at least two conveying elements defining a groove in which at least one tooth of said spur gear inserts; and a universal joint connecting said at least two conveying elements, said universal joint including a yoke having a hollow rectangular cross section.
 13. The device of claim 12 wherein said yoke includes apertures defining a vertical axis and a horizontal axis and wherein said vertical axis and said horizontal axis lie substantially in the same plane.
 14. A conveying device comprising: a base; at least a first spur gear rotatably affixed to said base; and at least two conveying elements extendable from said base and each including a cargo roller, at least one of said conveying elements has a supporting rail substantially parallel to an axial direction of said cargo roller associated with said conveying element, said at least two conveying elements defining a groove in which at least one finger of said spur gear inserts.
 15. The device of claim 14 wherein said base includes a conveyor belt.
 16. The device of claim 14 further comprising a second spur gear rotatably affixed to said base wherein at least one finger of said second spur gear inserts within a second groove defined by said at least two conveying elements, said first and said second spur gears affixed to a common shaft.
 17. The device of claim 14 wherein said first spur gear has a diameter of about 19 inches and includes a plurality of fingers with a pitch of approximately six inches between said fingers.
 18. The device of claim 14 wherein said base includes an actuator for providing inclination of a continuous belt, said device further including a plurality of conveying elements positioned beneath said belt, said device further including powering means for rotating said cargo rollers.
 19. A conveying device comprising: a base; at least a first conveying element having a supporting rail and a cargo roller positioned above said rail, said supporting rail having a rack element; a drive means for engaging with said rack element to extend said first conveying element from said base, where said supporting rail is substantially parallel to an axial direction of said cargo roller.
 20. The device of claim 19 wherein said drive means includes a spur gear rotatably affixed to said base, said rack element having a rack wall against which a tooth of said gear engages, said base further including an actuator for inclining said base, and said drive means includes a hydraulic brake. 